IR hole 109 is provided iii the upper surface of the cover 82 'to nermit the interior of the transdi-icer to b-- evacuated of all -ases the a-,cess hole 109 then being sealed with solider. After sealing, atmospheric pressure introduced into the interior of the bellows 95 throti,-h the threaded aperture 86 and the hole 39 will cause the bellows to tend to expa-.id. The effective area of the bellows ard the system stifi-,.icss is slch that 0.004 inch of relative moveriient of the bellows surface 96 aid 97 is typical. The crystal bearr. sensor 40 is then deflected 0.002 irch ov,@rcenter in the direction opposite to that caused by the bias spring adj'ustment (i.e., the beam is deflected upwards). If the absolute pressure i-.itroduced into the threaded aperture 86 is gradually redticed from oneatmosphere down to zero, the bias sprin,-, crystal beam sensor, and bellows system will in unison relravel the 0.004 inch to the init;al preload,-d position. At an37 point i-.1 between, there w;il be an equilibritim belween the force exerted by the "sprirg" system and the summed force due flo the pressure diff-crence between the bellows interior and exterior over the b-.Ilows effective a;ea. Simultan--ous with the bellows movement is a liri@,ar cl-iange in strain in the -auge are,i of the crystil bcai-i sensor. Tiie strain chaii-e caus--s an el-.ctrical resistance change of about nlus or minus 70/0 in gaii-es. The electrical circuit s@own in FIGURE 13 is utilized to detect this resist-cince chan.-e as a bridge unbalance volta-e. Upoii remembering that th.- lenrtl-t of the crystal beam sensor 40 is only 1/2 inch, it is repdily appareiit that the illustrated,presstire transdticer can be very compact, a volti-!-ne of less than 1/2 cub-'@c inch and a v,7eight of less than I ou:lce bcing easily obtain,,)bl--. Utilizing a 15 p.s.i.a. range, ',t is easily possible to obtain 0-2 volts output with 20 volts input without the use of auxiliary amnlifiers, as compared wilh a typical full range ou'put of 0.04 volt witla a 10 volt,input for a wire str,-,in ga,,i,-ebarometer. N-,I'Ilcn utiliziig the illustrated pressure transducer as a microbarometer (15- p.s.i.a.), the relatiie stiffnesses or sprin.- rlites of the b--Ilows 95, the crystal b-.am s-,nsol,!O, -,nd biis sdring 1'-, I are respectivel@v 1, 0.7 ai3il 3.3 tinits. wl-,ere I uii;t is ec,,,,i.@,alent to a p-rcssiire of 81 pol,inds per inch. The total or system spring rate in tile operatin- direction ;s 5 un;ts, or 5 tilnes the bellows st -Ctll,,SS. Ne-iLher the system s-,r;n.- rate .qor its linearity arkopreciably altered by the biis-s-orin--- actio-@i or its adjustment. Tb@e most highl@y stressed member of the system is the cryslal b,-am sensor 1,0. S-ingle crystal silicon is bysteres;s fr-,e, and the systein hysteresis is minim-l:zed by k-.-eping the op-.ratin- stress,-s low in the bellows and in the biis sdr;ng. The perpendicular align-ment of the bias spri,ig witli the crystal bea-n sensor provides lateral support in tie cross-axis dir--ction (transverse to the operating axis), so tliqt th-. system is relati@rely immune to vibratioi-i. 1- @i a,-I..Iitioti, dile to the sirall physical size of the b-,irometor, the lowest resoiiant f.- equency alona. any axis is in excess of 2.000 cycles ner secoiid, a resonant freconsiderably hi.oher than that of most b,,ironicters. Therefore, the illustrated pressure transducer is rugged as well as cor@ipact arclseiisi'live. Thu.-s, t,iere has been d,-@scribed hereinabove novel piezorc,sis@-1ve scinsors of ilite.- ral crystal construction, to.---ther with a novel practical embolimei)t 6f the;r tise in a presstir-- transducer. The il I lustrated cr@ibodiments of the p,.ezoresistiv,- sensors provided four active gauge ele m.-r-ts properly oricil@,.-d and ir@terconnected for use in a I .Lour.arm brid-c circuit. l@, is readily apparent, ho@Nev--r, that the present nve-@ition strtictural coiicedts can be utilized to provid-@ s,ii,-Ie crystal piezoresistive sensors liavillI a di.Fi-ere@it nurqber of.active gau-es. For example, n-icrely by cuttin-, i@i half t,ic sensors illustrated in FIGURES 9 ,ii-@d 1 1 of tl,,- drawing a'@oiig the lon.a;tudinq @zroove 31, a pe.4r oir two-ga,,l-,e sensors would r.-sult, the two arm 3,160,844- 12 circuitry reaulriii,- oqly three electrical leads instead of four. Also, difi'erent conslruction techn;ques -nay be followed iii the ftbr,.-,ation of the present inv--Dt:oii piezoresist;@Ve sensors. For exaiiaple, flbrication n-i-ight be simplified by constructing the piezoresistive sedsor in the form of upper and lower beam h,-:@Iv-;;s a@7,d cementing the halves to-et@ber alo-@ig the neutral a,,is of th-, resultant sensc)r beam. SuCii a procedur@, would s;mpli-,'Y the foi-mation io ot ttie @,ariols -@@ooves and -.ttac,iment of the electrical cc-n@Lacts a.-id le!@ds. Of cou,,se, al'Lhoti,@,,h a feature o:,' the illti-.trated embodimciits provided ail of the electrical coiitetcts on oic beam sL@.rface, some of the contacts cculd be prov-;,,'ed oil opposiii- bec-,m s,,irfi@ce where the ac13 ii,,e gau,-Cs are p'-)s;tioned. Furthermorp-, the concept of @-, l@Our -@ctive arm syste-rii '@s also -applicabic to conv-,-@itioiia-Ely bonded SCM;CODductor strain aauges, each activ.- gau.-e element be@r@-I mechanicplly bo-@ided to the proper surface o'L a beam. T',-lus, althougl-, the in20 ventioli lias been described w,'tli a certa@'@n degree of particularity, it is ,iiiderstood that tli@- present disclosure iias beei iiiade only by way iof example and thit,,iuiii@-rous cha,.-I.-cs in the dctai-s of consrli.-tion and tLe coiiibiii,,itio@i @,,iid ar---aiigemcri-' of parts m-,iy be resorted to with2,5 otit d,-partiii,@ from t'@i.- spir;t t-li,- scope of the in@,enlio-Ti as hereinafter claimeci. '@,Vhat is c"aiiii-,d is: 1. A s%-,,@iiicoDductor st.-a-ir,. gauc7-, CO@'riDrsing: (c,) aii clongate single s@-miconduclor crystal ;ot pre@-,elermined cryst,,il@io-r,,iDh;c orien'@atio-,i @ind ol a fiest i)red,-terniined condu@ctiviiy tyr.,e, said sem-icolilucter cry-.tal dei@n;n,- firs' iid second opi)osed Ion.-itu--'in-al surfaces, -irst ai,,d secoqd loii,-7@ttjdiDal s,,ir-faces ancl 'the end surfaces of s-,i;ci containiir @5 thereiti active im,-Lir;ty atgins of a secoild pred.- termined co!-iducVll:lty type to thereby define a shallow p@-r-PlIl -i er-,il sti.-fac-. band o'L said secoid predetermir@ed con,-'-Lictivity type loiagILudir@ally croirelitig said crystal exclu,@,.ve, of its longitudii-ial edf.@e sur40 face, said peripheral s-Lirf,,Tce bind of said s@-.cond predcterii-iiied co,,Pductivity type be;ng c-icetrici'@ly isolated frori the re.-iiainir.,g first cond,,iclivit@y t,li"3e i?ort;c@i of said crystil by the higti imp.-dancf-- b.-rrier provilled by the juiictic.;i thpr,-betw,-en, said crvstal 4:5 nL,@,ipg a plurality of predetermirc@i rooves iii the aiid c-@id -iir,laces tlie.-eojw-,ii@diy ibi-ou,@h sai-I sor@Lace and r)elietratiti@ the Linderlyiiig junct-.on, isaid grooves di@,ilin.- sqid b.,ind inlo di'screle el@ec@Irically -@'solated surface re-iors of 50 said second pred,termiiied @coi-iductivity typ--; and (1-,/) 0,, pitiraity of clec-'ricii coitncts, ohmically boi,,ded to predeterm".Ped roints on- E,- Ion-_itudinal surface of sciid body for copnection of clecttical meosuring circu;try theieio -for meas!,ire-riiciit of ciiaii.-es in 'the r@,3 el--ctrical resistance ol. sa,@-I discrete slirilace rc,,-ior,,s betwee-@l said coniac-s ii-,ion s'@rp-ssing ef sliid 2. A semiconducto.- stral-ii gauge comprising: (c,) I an elonaat-. sin,@le scmiconductor cristal of P tYPe -sil;co-Ti of LIOCil crysLa',Io.-raplii-- 60 said seinico@idtictor cryst-il defnill,@ fi.-st and secoi,2d o..nposed longitudir@,il surfaces, said --@irst and second lor@gitudinal surfaces aqd the end surfaces o@L Sl-id si'@icorl- cry-"Ll,L coiitai-Tiing therei@-i a--t,'.Ve -',oms of N tyric coi,@]@o@ccivity to threby defl-iie I 65 siallov@r peridheral sur-Lace baild of N type conduetivity longitudinally crcirciiiig said crystal -,xclus@ e of i's !G.,i,-i*ludin,,il sieic surfaces, said 1,1 tvde sur@@,tce ba@i,@: beill-, eleclrically isolated from tl,,e - remq,;niti, P type rort;on of said crystal b..-d3,, by the hi.-h i,,ii@o pedar@ea bar@rier provid,-d by @he PN ji-inction the,--- betweeii, sa@.'d crystal h,,tv-1r@.- a i)'Aurality of rreocgtoo-,,;es in tLe etid s,,ir.. face-@ tli@-reof exte@,acl.-Ing inwii-dly throtig'@i saic, N ty,7,c bc-tiid tnd -,@cne,rat'n@ th,-- Pi.I jiliac75 t' s@-tid groov-,s said. N typo bai-,d ir,b
@,160,@44 13 dl,,;crete electrically isolated N typ-, surface re.-ioais; and (b) a plurality of electrical co-iitacts olir@-iically boiided to predetermined points oii a longitudinal stirface of said body for connection o)' electrical measuring 5 circuitry thereto for r@easurement of changes in the electrical resistance of said discrete N type surface re.aions between said colitacts u,,)o-@l stressing of slid crystal. 3. A semiconductor strain -ail.-c comprising: 10 (a) an elongate sin.-le semicondurtor @erystal of N type conductivity of [111] crystdlographic oriertation, said silicon cryslal defining first atid second opposed longitudina.1 suri-aces, s,,iid first and second longitudinal surfaces and the end suriaces of said 1,5 silicon crystal containing 'Lherein activ-- impurity atoms of P type condu,ctivity to thereby define a shallow perinheral surface band of P type conductivity encirel-ing said crystal exellisive of its longitudi-@ial side surfaces, sa;d P tyl)c surface band being 20 clogtrically isolated from the remtinin.- N type portion of said s-ilicon crystal by the high impedance barrier provided by the PN junction therebetwec-@i, said crystal having a plarality of predeterr.,ii-iied grooves in the Icngitudinal and end surfaces - thereof 25 extending inward!3! 'Ll@iough said P type surface baiid and penetrating the underlying PN junction, said grooves dividing said P typc,@ baiid into discrete electrically isolated P typa stirface regions; and (b) a plurality of electrical coptacts ohmically bonded 30 to predeterniined po-nts on a longitudinal surface o-f said body f-or cornection of electrical m&-isuring eirciii'Lry thereto for measurement of cbanges in the electrical resistance of saitl discrete P type surface regioiis betnveeii said contacts Lipon stressing of said 35 crystal. 4. A sem,@'conductor strain gauge comprising: (a) an elongated single s-@miconductor crysta@l of predetermined crystallographic orientation and of a first predetermincd conductivity type, said senii- 40 conductor crystal defining first and second opposed Ion.-itudinal surfaces, said first and second longitudinal surfaces and the end surfaces of said crystal having diffused therein active iinpurity atoms of a second predetermined conductivity type to thereby -15 deflne a shallow peripheral surface band of said second predetermined conddctivity type lon,@itudinally encircling said crystal exolusive of its longitudinal side sur'taces, said peripheral surface band of said second cotiductivity type being electrically isolated 50 from the remaining first conductivity portion of said crystal by the Iiigh irnpedance barrier provided by the junction thereb-@twecn, said crystal havin.a a transverse groove near one end thereof extending across said first longitudinal surface, said groove extending 55 inwardly into said crystal from said first longitudinal surface through said peripheral surface band and penetrating the und,- rlying junction; (b) a first electrical contact ohmically bonded to said first longitudinal surface of said cry8tal at said one 60 end thereof adjacent said groove-, (c) a second electrical contact ohmically bonded to said first longitudinal stirface of said crystal adjacent said groove on the opposite side of said groove from said fa-st elpctrical contact; and C)5 (d) a third electrical contact ohmically bonded to said first longitudinal surface of said crystal body near the other end thereof. 5. A semiconductor strain gauge comprising: (c) @an el,-z,,-ate single semicondiictor crystal o@L P tyi,7e 70 silicon having a [1001 crystallographic orientation, said silicon crystal defining first and second opposed Ion.-itud,inal surfaces, said first and second longitud;nal stirfaces and the end surfaces of said crystal h,tviilg difl'uscd therein active impurity atoms of N 75 14 type conductivity to thereby define a shallow peripheral surface band of N type conductivity longitudiiially encircling sa;d crystal exclusive of its longitudinal side slirfaces, said peripheral N type surface band beiiig electrically isolated from the remainiiig P type portion of said crystal by tne high impedance barrier provided by the PN junction therebetween, said crystal having a transverse groove neqr one end thereof extendinp, across said first longitudinal surface, said groove extending inwardly into said crystal from said first longitudinal surface through said N type sur-ace band and penetrating the underlying PN junction; (b) a first electrical contact ohmically bonded to said first IcTg;tudinal surface of said crystal at said one end thereof adjacent said groove; (c) a s@-cond electrical contact ohmically bonded to said fn-st longitudinal surface of said cryst,,il adjacent said groove on the opposite side ol' said groove f-rom said first electrical contact; and (d) a third electrical contact ohmically bonded to said first longitudinal surface of said crystal body near the oth.-r end thereof. 6. A semicoiiductor strain gauge comprising: (a) an elongate single semicoiiductor crystal of N type silico-.,i having a [111] crystall@ograph;c orientation said silicon crystal deflning first and second opposed longitudinal surfaces, said iirst and second Ion.-itudinal surfaces and the end surfaces of said crystal havin.- diffused tlierein active impurity ato-m@ s of P type conductivity to thereby define a shallow periphcral surface band of P type conductivity longitudinally eileireling said crystal exclusive of its lon,@itudinal side suriaces, said peripheral slirface band of P type conductivity being electrically isolated from the reniaining N type portion of said crystal by the high impedance barrier provided by the PN junction therebetween, said crystal having a transverse groove near one end thereof extending, across said first Ion.- itudinal surface, said groove extendin.- inwardly into said crystal from said first longitudinal surface through said P typ@- sirfac@- band and penetrating the underlying PN junctioii; (b) a first electrical contact ohmically bonded to said first longitudinal surface of said crystal at said one c-@id thereof adjacent said groove; (c) a second electrical contact ohnlically bonded to said first long-@tlidinal surface of said crystal adjacp-nt said -roove or th-, opp-os,@'te side of s@@id gr,oove -from said first electrical contact; and (d) a tliird electrical co@itact chmically bonled to saicf f,@rst Ic-ngitudiral siii-face of said crystal boay n,-ar the olher end the-reof. 7. A semiconductor straiii gauge comprising: (a) an clon.-ate single semiconductor crystal of predetern-iined crystallo,-raphic orientation and of a first predetermined conductivity type, said semiconductor crystal definin.- first ard seco-Tid opposed longiti-idinal surfaces, said first and second longitudinal surfaces and the end sur@faces of said crystal having diffused therein active impurity atoms of a second predetermined;conductivity type to thereby define a shahow p-.rip@ieral surface baiid of said second predetermined coiidtictivity type longitudinally encircling said crystal exclusive 'of ills longitudinal side surfaces, said peripheral 's,,iriac-- barid of said second conductivity type bein.- electrically isolated from the remaining first conductivity portion of said crystal by th-- high ii-npedance barrier provided by the junctioil thei-,between, sa-ld crystal haxting first and secor@d third -rooves th,@rein, said first groove extending longitudinally peripherally around sa;d crystal through the lon,@itudinal surfaces and end surfaces thereof, said second groove being in said first surface hear oie end of said crystal
3ilGO,844 Is aiid extendin,- t@.-ansversely from sail first groove to one longit-adinal side sur-face of said crystal, said third groove being in said first Ion.-itudinal surface near said one end o.'L said crystal and extending transv--rsely from said first groove to tiie other longitu5 dinal side surface of said crystal, said grooves extending inwardly into said crystal ttirou,-h said p.-ripher,@il surface band and penetrating the underlyin.- junction; (b) a first electrical contact ohmically bonded to said 10 first Ion.-itudinal stirface of said c.-ystal at said one end thereof adjacelit said second groove; (c) a second electrical contact ohmically bonded to said first lon-itudi-@iai surface of said crystal body adjacent said second groove on the opposite side of said second 1.5 ,-roove from said first electrical contact; (d) a tliird electrical contact ohmically bo-iided to said first Ion-itudinal surfa-.e of said crystal body near the other end th--reof on one side of said f-@rst groove; (e) a fourth electrical contact obmically bonded to said 20 first longitudinal surface of said crystal at said one end thereof adjacert said third @roove; (f) a fiftl@l electrical contact ohmically bonded to said first longittidinal surface of said crystal adjacent said third groove o@i the opposite side of said third 25 ,@roove from said fourth electrical contact; and (g) a s:xlli el,@etrical contact oliniically bonded to sa@"c', first longittidinal surface of said crystal body near the other cr@d th,-reof on the other side of said first ,@rc,,ov,,. 50 8. A semicopductor strain gauge comprising: (,-) an cloii.-ate single semicoidulctor cry-.tal of P typc silicon h-,vi@-., a [1001 crysiallographic said silicon crystal deiining first and secoiid opposed longitudinal surfaces, said first and second longitu35 dinal surfaces and th-- end surfaces of said crystal havin- difftised therein active impurity atoms of N type condtictivity to thereby define a shallow p-.riptieral surface band of N type conductivity longitudinally encirelin.- said crystal exclusive of its loniyi- 40 tudinal side surfaces, said periph-.ral surface baiid of N type conductivity bein.- electrically isola'Led from the remainir@9, P type porl@lon of said crystal by the high in-ipadance barrier provided by the PN junction thereb--t@veen, said crystal hivina first and second and 45 third grooves th.-rein, said first groove extendi-@i-, loi-i.-itudinally perioh,-ral-y arour@d said crystal throu,-h the longitudinal surfaces and e-iid surfaces ,h.reof, said secopd -roove beiiig in said ilrst lo-@i.-itud@ina', surface near one end oj' said crystal and 50 extendin- transversely from spid first groo,,,e to one longitudinal side s,-lrface of said crystal, said third groove being in said first longitudiiial surface near said one end of said crystal and extendin.- transverse-ly from said first groove to the other - loi,,-,tur@ 5 dinal side surf,,ce of said crystal, said grooves extondin- inwardly -into said crystal through said N type surface band and peretrating the - underlying PN junction; (b) a first electrical contact ohmically bonded to said Go first Ion.-itudinal surface of said crystal at said one end thereof adjacent said second groove; (c) a second electrical co-,itact ohmically bonded to said first Ion-itudinal -@urface of said cryst,,il body adjacent said second -roove on the opposite side of sa;.d 65 second groove from said first ' electrical contact; (d) a third electrical contact ohmically bonded to said first lonaitudinal surface of said crystal body near the other end thereof on one sid@ of said fu-st groove; 10 (e) afourthelectricalcontact,ohmi --allybondedtosaid first loiigitudinal surface of said- cryst,,il at said one end tliereo'l adjacent said third grobve; (f) afifth electrical coiitact ohmically bonded to said first longitudinal surface of said crystal adjacent said -5 third groove on the opposite side of said third groove frorli said fourth electrical contact; and, (g) a sixth electrical contact ohmically bonded to said first longitudinal surface of said crystal body near the other end thereof on the other side of said first groo@,e. 9. A semiconductor strain gau,-e coniprising: (a) an elonga!C sei-niconcluctor crystal of N type silico-ii having a [ I 1 1 ] crystallographic orientalion, said s,'Iicon cryslal d4@fin'@iig first and seco-,id oppcsed lonpitudinal surfaces, said first alid second Ion.-itudinal surfaces and 't@e end s,,irfaces of said crystal having diffused therein active impurity atoms of P type conducti,,,ity to thereby define a shallow peripheral surface band of P typ-. conductivity longitudinally e@icircii,-ig saicl crystal exclusive of its loityitudinal side surfaces, said peripheral surface band of P type concluctivity being electrical'y isola'Led from thf,@ remai@ii@i.- N typo portion of said crystal by the hi,-h impedance barrier provided by the PN junction therebetnveen, said crystal having first and second and third grooiles therein, said first -roove extending longitudinally periphe;ally around said crystal through the longitudinal surfaces and end surfaces ther.-of, said second groove being in said first lon.@itudinal surface near one end of said crystal and extendin.- transversely irom said first -roove to one longitlidinal side stirface of said crystal, sa-id third groove b.-ing i-,i said first longitudinal surface near s,-tid one end of said crystal and extendin.- transversely from said first ,roove to the ol@her longitudinal side surface of said crystal, sa,.d 2rooves extendini,, inwardly into said ervstal through said P type surfac-, band and pene',ra@ing t@ic underlyir@.- PN junction; (b) a 'irst electrical cor@tact otimically bonded to said first lon-i@udinal surface of said crystal at said one eDd thereof adjacent sa-@d second groove; (c) a secor@d electrical contact ohmically bonded to said first Ion.-ituclinal surfac-- of said crystal body adjacent said sf--coid L,,roove oi the opt)osite sicle of said secf)iid -rbove )rom -z,, first clec'@r cal contact; (d) a third electrical contact ohmically bonded to said first loiigitudinal surface of said crystal body near tiie other end thcrc,,)f cii oic side of s,-,id firs, -roove; (e) a fourth electrical contact ohmically bonded to said first longitadinal surface of sa;d crystal at said one end thereof ndiacelit said third groove; (f) a fifth electrical contact ohmically bonded to said firsl longitudinal surface of said crystal adjacent said third groove on the opposit-. side of said third groove from said four@h ciectrical contact; and (g) a sixth elecir:ical contact ohmically bonded to said first longitudinal surface of said crystal body near ttic olher end thereof on the o,,",@er side of said fir@t groove. 10. A semiconductor s,-aiii gau-e compr.,sing: (a) an elongal,c s;ngl,- semiconductor crysfal of predetermiied r-rystal@log@-aphic ori,-ntit;on a-,id o,l a first predetern@ @@r,@-zd co-,i,- ],,lctivily type, said sediicoqduc"cr crystal defining Pzst and second orposed lor@-itud;nal si-irfec@-s, sa@d f-,rst and s@-cond lonf,,i@Udiriil surfaces a-@id the etid s-ari-aces of said crys'@al having,d,..ft'used tii,-rein act@'.ve impurity atoms of a seco-@id - orejetermir-led condiictivity type to the.-eby define a shallow peripheral surface band of said secoiid predetermined conduct,'.Vity type loiigituditiallv oneirel..ng said crystal exclusive of it3 lopgitudi@ial sid-, surfaces, said p-@riphcral s@ariacc band of sa;d second conductivily typo b,-,ng elec@ricallv isolat-@d from the rem@ai@-ii-iig fii-st conductivity portion o@ said crys+al by th-- hi.-h ii-ar-edance barr'@or r,,-o7i;d,-d by 'he j,,lqction ther,,betwe@--ii, said cryst-,il b,,ining first ajid second and third iiiicar gi-ooves therein, said first LI-@icar -,roove be@iiining at a 1-irst rredetermined po;@--t on sa;d first
17 longitudinal surface riear one end of said crystal and extending lopg-itudinally peripherally around said cr@rstal along said surface baiid to a secoiid predeterniined point spaced apart.Lror@i said first predetermined point in said first longitudinalsurface, said second groove bein@, in said first longit-adinal surface and extending transversely from the end of sai-d first groove at said rirst p.-edeteriii:,.i-,,l 1--.oiiit to one loilgitudiiial sio@e si.[Ff@ice of said crystal, said tliird groove being in s-,iid first longitudinal s,,irface and ex'Lending trtnsversely f-rom the other end of said iirst -roove at said second predetermined point to the otler longitudinal side surface o,4 said c@ryslal, said grooves extending inward,ly in',Io said crystal through se-,id surface b@and ,9,nd penetrating the underlyin.- junction; (b) a first electrical conlctct ohmicilly bonoted to said first longitudinal surface o'L said crystal near said one lon,gitudinal side surface tliereof between said second groove and said one end thereof; (c) a second electrical contact o!Lmically bor@ded to said first Ion.-itudinil surface of said orysta@l iiear said one longitudiiial side surfa-,e il-iereof proxiiiiate the other end thereof; (d) a third electrical contact ohwigally bopded to said first longitudinal surface of said crystal near said other longit,,Tdinal side surface ther--of b,-tweeii said third groove and said otie end thereof; (e) a fourth elect-rical contact oh,--iifally bondea- to said first longittidinal surj',,ice of said crystal near said other loiigitudi@ial side surface thereoi' adjacerit siaid third grooie op the opt)osite ,icle of said tiaird groove from said third electrical contact; and (f) a fifth elect@rical coiitact ohmically bonded to said first lon@giluiinal @surface of spid crystal near said otlier longitadinal side surface thereof adjacent said otlier end thereof. 11. A semicordugtor str,,iin g,).uge corrprising: (a) an dongate single semiconductor r-rystal of P-type silico.-i Laving a [1001 crystal',o-raphic crieiitation, said crystal def-@iiing iirst a,,.d seec-r@d opposcd longitudinal surfaces, said first and second Ion.-itudinal surfaces and the and surfaces of said cryslal liaving cl@'@iTtised therein -,iclive irc@purity atoris of 1,Ttype condtictiv;ty to ther--by define a shalloiv peripheral surface band of N type condlictiv-lty longitudinally encirrling said crystal excILsivc, of -its long,"tudinal sic;,e curfaces, said j)er;pl@7eral bai-id of N tyr@e condue,tivity being electrically isolated from the remaining P type portion of said o.-ystal by the high impedance barrier provided -by tL-c PN junction tlierebetween, s-,Lid crystal having fi@rst and second and third linear grooves th--rc@in, sa-ld first li@iear groove bcgii-@nin.- at a 'iqrst I)rede@ermined l@oin" on saicl first longitudinal surface near'one end of sai@ erystqlard ex@endin.a longittidinal@ly puipherally around said crystal a:long said N type surface band to a seco-tid predeterm@'@ned ipoint spaced ap-art frol@i said first predetermined point in said first longituclinal surface, s-,tid second @.-roove being in said first lorigituclinal surf,,ice and cxteiiding transversely from the end of said first groove at said -predetermined point to oiie longit-adinal side slrface of said crystal, said third groove being in said firqt lop.-itudinal sur-'.ac-. andextendin,-, trarisverscly 1'fom th@- other erid of said first groov-- at said second prcdetermined poiilt to the otti.-r loncitudinal side stirface of sa'Ld crystal, said grooves extc-iiding '@v,,liardly iiito said crystal through said N t@rp.- stirface band and peTietrat,'@ng th-. underlying PN iiinction; (b) a @qrst electrical contact ohmically bonded to said firs', longitudinal surface of &-tid crystal np-ar said otic loii-itlidir@al side surface th-,rlof bet@lieen said secoi,d groove 2,@-id sa,@d one -,7iLl li@@,-reof; (c) a second electrical coptact ohmically bo.7ided to said first lonpitudinal surface of said crystal near sa,;d 3,160,844 19 on-, longitudinal side stirtace proximate the oth,-r end thereof; (d) a third el@-ctrical coqtact obniically bonded to said first longi'@udinal surface of said crystal near said other !on.-itudilial sid,- surface thereof between said third Eroove ind said o-@ic eDd thereoll; (e) a fotirth cleelrical coiicact ohmically bonded 'Lo said first tongiludi--qal surfac,-- of saiu' cryst,-@'i nepr said other longitl,(iinal side slirface thereoi adjacent 10 said th;@rd groove on the opposite side of sa;d thii-d Iroovo- said th@rC,, electrical contact; ard, (f) a fifth elec',rical ccjitact ohmically bo-ided to sa'Ad fir.@t longitlidiiial surface of said crystal near said o'@hp-r Ion.-itud;.11-.l side si-irface thereof adjacent said i5 otlier -iid thereof. 12. A seiiiicondtictor straiii gauge conaprising: (a) m elo-@igate s-irigle ser-,iiconductor crystal of N type s@'@izon of [1111, crystallograrhic orientation, said silicon crystal defi-,iirig first and secotid opposed 20 longitud;nal surfaces, sa,,'d f@rst and second longitudinal sur.L'aces aiid th-, end surfaces of s,,iid crystal having dift,,ised therein active iiiipurity atoms of P typ@- coiiductivity to thereby define a shallow peripheral surface band of P type conductivity longitudinal25 ly ericircling said crystal exclusive of its lon,@itudinal side surfaces, said peripheral surface band of P type conductivity being electrically isolated from the remainin.- N type portion of said crystal by the hi8h iinpedance barrier provided by the PN junctio-@l there30 between, said cryslal having first and second and third linear grooves thereiii, said first linear groove beginning at a first predetermined point on said first loiigitudinal surface near one @-nd of said crystal and extending Ion.-itudinally peripherally around said 25 crystal alon.- said P type surface band to a second predetermined point spaced apart from said first predetermined point in said firstlongitudi-iial surface, said second groove being in said first longitudinal surface and extending transversely from the end of 40 said first groove at said first predetermined point to one Ion.-iLudinal side surface of sa:d crystal, said th,rd groove bein@ in said first longitudinal surface a@n@ extending tra'nsversely from the other eiid of said first groove at said second predetermined point 4,@ to the other longittidinal sid.- slirface of said crystal, said grooves extending inwardly into said crystal through said P type surface band and peiietrating the underlving PN junction; (b) a first electrical coiatact ohmically bonded to said 50 first longitudi-@ial surface of said crystal near said one longitudi-@ial. side surfac.- thereof between said second groove and said one end thereof; (c) a second electrical contact ohmically bonded to said first longitudinal surface of said crystal near 55 said oiie longitudinal side surface thereof proximate the otlier end thereoj-; (d) a third electrical contact ohmically bonded to said first longittidinal surface of said crystal near said other longitud@@'nal side surface thereof betv,,een said 6( third, groove and said o-.ie end thereof; (e) a folrth electrical contact obmically bonded to said first Ion.-itiidiiial surface of said crystal near said other longitudinal side surface thereof adjacent said third groove on the opposite side of said third groove cj5 from said third electrical contact; and a fifth eelctrical cottact ohmically borded to said first longitudiiial surfac-. of said crystal near said other longitudinal s;de surface thereof adjacent said otlier end thereof. 7o 13. A trarisducer structure comprising, in combination: (a) a-@i clon.aate semiconductor beam freely supported at its ends, said beam cons:@sting of an elongate single semiconductor crystal of predet--rmined crystallo75 grat)llic or,'@entation and of a first predetermined con-
ductivity type, said semiconductor crystal de'@ining first and second opposed longitudinal surfaces, said first longitudinal si-irface having diffused therein discrete shallow regions of a second p.-edetermined conductivity type electrically isolated from each other, 5 said diffused regions longitudinally extending lengthwise of said semiconductor crystal, said diffused regions being electrically isolated from said first t)redetermined conductivity type portion of said crystal by the high impedance junctions therebe,,N'Veen; 10 (b) a plurality of electrical contacts ohmically bonded to said diffused regions near Ion.-itudinal ends thereof to provide each of said diffused regions viith an electriclal con@Lact near each of its ends; and (e) force-summing means contaclinp. said beam inter- 15 mediate its ends and movable transversely th,- reto in response to predetermined forces whereby application of said predet@.rmined forces to said forcesumming means causes movement ol. said forceslimmi@ig means transversely to said beam to tboreby at)ply a 20 tensile stress to said beam and cause a varia@ion in the clectr@.cal resistance of each of said diffused regions, which resistance variations caD be measured by electrically intereoinect@.ng said electrical contacts so that each of said diffused re.-ions forms a different Q- 5 leg in a Wheatstone bridge circuit. 14. A transducer structure comnrising, in corpbination: (a) an elongate beam freely suppor'ted at its ends, said beam consisting of an elongate single semiconductor 30 cryst@l of predeteri-nined crystallographic orientat@'.on apd of a first predetermined condtictivity type, said semiconductor crystal defining first and s@-cond opposed lonpitudinalsuri-aces, said first and second longitudinal surfaces and the end surl'aces of said 35 crystal having diffused therein active iniptirity atoms of a second predeternined conductivity type to thereby define,a sballow peripheral surface band of said second predetermined cotiductivity type longit,.idinally encircling said crystal exclusive of its longitudinal 40 side surfaces, said peripberal siirface band of said second conductivity type being electrically isolated from the remainina first condlctivity type portion of said crystal by the high impedance barrier provided by the junction therebetween, said crystal hav- 45 in.- a transverse groove near one end thereof extending across said first longitudinal surface, said groove extending inwardly into said crystal from said first loilgitudinal surface tbrough said si-irface band and penctratin@ the underlying junction; 50 (b) a first electrical contact ohmically bonded to said first longitudinal surface of said crystal at said one end thereof adjacent said aroove; (c) a second electrical contact ohmicab'y bond-.d to said first longitudinal surface of said crystal adjacent 55 said -roove on the opposite side of said groove from said first electrical contact; (d) a tmrd electrical contact ohmically bonded to said first longitudinal stirface of sa@@d crystal body near the other end thereof; and 60 (e) force-siimming means contacting the first longitudinal surface of said crystal beam interriiediate its ends and movable transversely thereto in response to predetermi-.ied,forces w.iereby adplication of said predetermined forccs to said force-summing means 65 causes movement of said force-summing means transversely to said beam to thereby apply a tensile stress to said beam and cause variation in the electrical resistance of said peripheral surface b,,ind belween said electrical contacts. 70 15. A transducer structure comprisinf@, in combinaticn: (a) an elongate beam freely supported at its ends, said beam consisting of an elon-ate single semico-@iductor crystal of I)redet-- rmined crystalloe-raphic orient-,ttion and of a first predetermi-@ied conductivity type, 75 said semicorid@,ictor cryst,@il defiiiila,- and -qe-,ond ., Pi sL opposed @lon.-itudinal s@.irfaces, s-.id iirst aid second in-ti.-itLidinal surfacp-s atid the end surfac,-s o'l said crystal hoviig difftised ther--in active irr@ptirity atonis c," a socond predet-.rm,',i,@fd co-iiductilvi'L,,, @type lonL!,"iiidin,-,Ily encircling crys'Lal ex,-Iusive of its lon-iti-idinal sid-e sur-'caces, said peri,@heral surface ba-id of said s,-cond copdLi-"Ivity type beiiig electrically isolated from the rerv-iaining first coid,,ictivity typ-. portion of said crystal by 'he hi,-h iwpcdance barrier prc)vided by the unctioi therebetwe@-ii, said 'irst lo-r.,,itudinal surface f@,rst and seconl and tl'ird groov,-s tlicreiii, said first groo,/e exteridi-ng pp-rip.-f.-rally arolind slid crystal beam tliroug'ii the lor@,fzitudiial stirf,-,c--s ind eiid surfice tboreof, s,,iid seco@id groove bei@-,- iii said first lon-itudiriql surfEt.(,c iiear one epd of sp.-Id cryst-.1 and ex'Lend,na transversely from said P-rst groove to one p longill, inal side surface of said crystal, said -third groove being in said first loj:igitudi-@ial slirface near siid one etid of sa;d crystql ar@d c-,terlding transversely f,-oin s,,,,'@d first g.-oove to the other longitudinal sid@. stirface of sa;d crystal, said grooves exteno,@ing inwardly irto saiti crystal throljgl-i said surface b,,ind aid pen-,tratiiig the underlyiiag jtiiiction; (b) a iirst electrical contact ohiiiically bonded to said @'i r s' loti.-ittidiiial surface of said crys,al at said on-, eid thereof ad;acznt said seco@i(Igroov@@; (c) a secoid el,-ctrical contict ohmically bonded to s-aid Drst longiVi-",.'Pal silrface of said crystal body aijace-nt said seco-@iO, groove on the opposite side of said second groove irom said @'irst cl@ectrical contact; (d) a third clect,-ical coitac@ olimically bonded to, said first loiiE,,itud;pal surface o-F sa;d crystal body near the otlier end tliereff, on o-iif,- side oi- said first @-yoove; (e) a fourth electrical contact ohmically bonded to said ilrst Ion,-itudinal surfac-. of said cryslal at said otic c-@id thereof adjacent said third -roove; (f) a fifth electrical contact olin.-iicahly bonded to said first '.op.-iLudiral s@,irface of s-,irl cryst-,il adjacent said t'@iird groove oq t,@e opposite side of said third groove from said fourth contact; (g) a sixth electrizal contact ohiiiically bonded to said first longil@tidinil surface of said crys@lat body near the other end thereof on ihe other side of ,aid first groove; and (h) force-summing mcaiis contactirig the -@'irst lotigitudinal surface of s-,iid crystal b,- am intermediate its ends and movable tra-@isversely ther-to in response to predetermined forces whereby application ol' s-,tid predeterrpiii,-d forces to sa-'Id force-sumn-ing means cquses riiovoiner@t of said force-summing means trar@sversely to sa,.d beam to th,-reby apply a tensile stress to said beam and cause variation iii the electrical resistance oL' said peripheral surface band between said electrical cotitacts. 16. A trapsdue-r structure comprising, in coinbiiiation: (a) an elongate beam freely supported at its ends, said @beam co-.isisting of an clo@,i,-ate singl@ -,einico-TidLi 'elor crystal of Dredet,-r@iiined crystallo,-,raphic ond of a first predetermined co@10,ucLivity type, said sernicor@dtic'Lo--,- crystal definiig and second opposed longitudiiial surfaces, said ilrs" and second long--fuei-@ial stirfaces and the end si-irfaces of said crystal hai7ing diffused therein active ;mpurity aloms of a second predetermined conductivity type to thereby de'iie a shallow oeripheral surface band of said socg.,id predetermi@ied cor@ductivity type longitudinally encircling said crystal exclus@@l'e of its Iongitudinal s:lde surfaces, said pe:.-ipheral surface band 0 4 t said sec@ond conductivity type being el@ectrically isolated from the remaining first conductivity tljp!.por,,ion of said crystal by th-@ high impedance barrier by the junction th-,rebetN@,ceil, said crystal ii,,ivin,@ first and second and third linear - .rooves therein,
21 s,,iid first Iiiiear .-roove beginning at t i9rst predetermin,-d poilit on said first longittidinal surface near oiie end of said crystal ar@d oxtendin@,, longituditially peripheraliy aro@,irid said cryslal along said srrface band to a second predeterm;ncd i)cint spaced apart from said first predet,-rmined point in said fi,,st ll,)ngitudinal surface and extending transvers-,Iy )'rom the end of said first groove at said fir@,t predc',crmiiied point to one longitudinal side s@,irface of said crystal, said third groove beiiig in sa-@d tirst longitudi-iial surface and exterding '-.raiisversely from the r-,ti7,er ciid of s,,iid first groove aL said second predeterni-ined po@,nt to tho other lon- ttidiiial s-'de su,@:f ace o' said crystal, said grooves extending inivardly inlo -oaid crystal through said stirface baiid and penetratj-.ig the uiiderlying jlinotion; (b) a first electrical contact ohrr@ically bonded to said first longitudinal surface of ,aid crystal near said one longitudin-d side surfai-e thereof between said second groove and said one end thereof; (e) a s-,cond electrical contact olimically bonded to said first longitudinal surface of said crystal Ticar said one longiti-idir@al sid-- s-,irface tliereof proximate the other end ther.-of; (d) a t]3ird electrical contact ohpiically bonded to said first loigitudinal si,-r'ace of said crystal rcar L said other loDgitur-Iii-i-,il side surface lherec,c be,ween said third groove and sa-ld one or@d 'thereof; (e) a fourth electrical contact ohrilically bonded to said first lon,@ic,,idinal surface of said crystal near said other Ion.-ittidinal side s@,irface tliereof adjacept said third groove on the o;)posite side of said groove from said third electric,,tl contact; (f) a fifth electrical contact ohmically bonded to sa, '.d first longitudinal surface of said crystal ii,-ar said ,other longitudinal side slirface thereol' adjncent said other end thereof; and (.-) force-summing mea-.is contacting the first longit-Lidinal surface of said crystal be,,im ivitermediate its ends and movable transversely thereto in res,@otise to predetermined forces vvhereby ipplicqtion of said predetermined forces to said force-si-imming means causes movement of said force-summ;n,- means transver-.cly to said beam to thereby apply a tensile stress to said beam and caiise @a,.7iation iii the elec,Lrical resistance of said i)eriph.-ral sutface band betwee-.i said &iectrical contacts. 17. A pr-,sstire transdlcor comprisin- iii combination: (a@ a transdiicer housing cons,stitig of a base member i having a generally clip-shaped c-@ver hermetically scaled ',hereto, said base member defining a pressure port extending therethrough - commi3i,:Ical@i,-@g with 'tiie iiiterior of said housing; (b) a bellows defining an exp@t-.isible air chainl,)-@rterminating in an air inlet port, said bellows being hermetically scaled to said base me.,nber periph-ertily encir-.Iing said pressure port viithin said hoi-isin.- witli said a@'@r inlet port communic-,tting wit'i said pressure port; (c) ar. elongate rigid bar mounted by one of its ends for Ion-itudi-iial linear movement uoon expansion and contraction of said bellows, said bar defining a ti,,,insverse generally rectan,-,,ilar @iotch near its other e-rid" (d) a piezoresistive se-iisor in the form of an clonga',e bc;am supported at its end within said housing with the c-,ntrat portion of said b-- am wiihin sa;d ti-ansverse notch in said bar; aiid (e) spring biasiiig means moi,,nted within said liousiiig, said si3ring biasin@ means bein- selectively adjustable to provide a predetermi-iied force tipon said other end of said rod. 18. A pressure @ransducer as deiined in claim 17 xvhcrein said beam consists of an clo-ilgate single semi-conductor crystal of predetermined crystallogra-ohic orientation and of a first predetermined conductivily type, said semicon3,160,844 22 ductor crystal defini@ig first aiid se-,ond oi)posed lon@-itud:nal surfaces, said f@rst and second lor,.gitudinal surfaces and the end surfaces ol' said crystal containing therein active imptiri*,y atoms o4L a se-cond predetermined coner,,ctivity type to thereby defiiie a shallow peripheral band of said second predetermined conductivity type lon@-itudii,.ally ciicirclinsaid crystal excltisive of its longitudinal side si-irfaces, said surface band of said second -oredeterm,'@ned conduc-tivity typ-- being electrically isolated froiii 10 remaining first condL7ctivity type portior@ of said crys@al by tLe impedance barrier provided by the junc@,.on ther-,between, said crystal haviii- a plurality of pred-termiiaed grooves in the longit-Lidinal and end surfaces t@ereof exteriding inwardly throlgli said band and pene15 tratiiig the underly;llg junctioii, said grooves dividing said band into discrete electr;cally isolated surface r".ions of said secord prede'Lermined conductivity type, said crystal having a plurality of electrical connectors ohmically bonded to predetermined points on a longitlidinal surfa ce 20 o'L said crys',al for conrection of electrical ineasuring crciiitry thereto for measurei-neilt of c.1a,,in.-es in the electrical resistance o@' said discrete surface regions between said coiitacts upon stressin.@ of said crystal beam by said rod upon mov,-ment of said bellows. 25 19. A pressiire transducer as defined in claim 17 whereir@ spid bcain consists of an elor,.-ate single semiconductor crystal of predetermined crystallograp]2ic orientation and of a first preletermined conduct-'Vity type, said semiconductor crystal defij-.iing fi-rst ard second o-oposed Ion-i30 1 "Idina' . surf aces, said first and second longitt@dinal surf ac'es iiid the end stirfaces of said crystal having diffus-.d therein activity impurity atoms of a seco-.id predeiern-iined condtictivity tyr o to thereby define a shallow peripheral sur35 face baiid of said seco@id predetermined conductivity type loigitudiiially encircliig said crystal exclusive of its longit-adiral side s-,irfaces, said peripheral surface baiid of said seco@id coiductivity type being electrically isolated from the remain@'ng first conductiirity type portion of s.-.id crystal by the 1-iigh impedance ba@-rier provided by the juiic40 . t@@on therebe'cwe-,-i, said c2ystal havin.- P@r--t and second and tliird grooves therein, said first groove extending longitidirally pe@-i,,)I-erally around said crystal through the longiludinal surfaces ar@d end surfaces thereof, said second 45 groove beiiig in said first long:tudinal surface near or@e end of said crystal a-,.id extending transversely from said first groove to one loigitudinal side surface of sa;d crystal, said third groove being iii sa-d first longitudinal surface near said o-@ic of sa'td crystal and extending transv--rsely from said groove to the other long;tudinal side sur50 face of said crystal, said crys'al h-,tviig six electrical contacts ohm,'cally bonded to said f@rst longitudinal surface therec)f, the first electrical contact being b@,nded to said firs' lor@git@-id@'nal si:,rface near said one eiid of said crystal adiacent s-,id second -roove, the second electrical contact 55 bei@-i,,- bord,-d to sa-d iirst loiigitudinal sur'ace near said oiie ciid of sa,"d cry'stal on the ottier side olf said second @roo@tc,, from said first el,c(rical coiitact, th-. third electrical con'act beino bo@ided to said first longitudinal surface ad;ace@it the other end of said crystal near said one 60 j loigit,,Tdinal side stirface thereof, 'Lhe fourth electrical contact bei-.lg bonded to sa,'@d first lon@itudinal surface near sa@d one er@d bf sa-,d crystal adjacent said tbird groove, the iillth clectr,cal contact bein.- bonded to said first longitucii-iial slirface near said one end on the oth-,r side of 65 sa;d third groove irom s-,iid fourth electrical conlact, said sixtla electrical contact being bonded to said -iqrst lor@gitudii,.al surface adjacent said other end of said crystal near se,@ 'd other longitudinal side surface thereof. 70 20. A pressi.,re transdii-cer as deiined in claim 17, whereiii sqid be-am cons;sts of an elongate single semiconductor crystal of predetermined crystallo.-rapliic orienta' ion aid of a first predetermiiied cond@uctivi@Ly type, said semiconductor crystal definin.- i9rst and second opposed 75 loiigitudilial sur-,aces, said first and second longitudinal
surface,s and the end sur4,ac--s of said crystal hpvin.- d ffused therein active impurity ttorqs of a second predetermined coadil-ctivity type to thereby deiin@,- a shal'@Ow peripheral stirface ba,,d of s-,iid secolid @rjred.,ter-qiiiied conductivity type longiti-,d-in,- clly enci@rcling saii cryscil P--xclusive of its Iongittidinal side surfaces, sail peririier@1.1 surface band of said @seco,.id coiicluctivity type beir@.- el.,@ctrically isolated -from the remairiiig first conduct@vity typp. portion of staid crysta:l @,by th-, high imp--dancc-, barricr provided by the junctioli therebetween, said crystal ha,@;ng first and second and third linear -rooves thereiii, said first linear groovebeginning tt a first predetermined )o,',nt on said first longitl,.dinal surface ii,-Pr one elid of saicl crystal and exlending loTigitudi:@i,)Uy p@-r@,rherally around said crystal alorg s@aid surfar-,3 band to a seco:id predctermined point spaccd ap,art from said -oredeermircd point in said flrst longittid,nal sLrf,,ice, said second gi-oove bein,-, in said first longitud,',T-ial surface and extendin- transver-sely from '@he end ol' said first grc-ove at sa@'d 'irst predetermined point to otic longit-adinal side siir-@acc of s,'@i,,l crystal, said third groov@, b--ing in said first i-,ngit-c@,-';nal surface and extend;ng tra-,isve-,,:sely from the other end of said first - row@e at said second predete:rmilied poidt to the otherlongitudinal side suri'a-.e o]L sa-.d cryst!.ii, said crystal havin- five electrical contacts ohm,'@cally bo-iided to the first longi@,Udinal surface thereof, the first cal contact bein.- bond,-d to said first lor@gitudinal @,zi-irface between said second Lroove and said or@@- end of sa,' ,d crystal, the second electrical contact being bonded to slid first longitadinal surface adjacent the other end of said crystal near said one longitudinal s,'de surface th--reof, the t@hird electrical coptacl beina bonded to said first longitudinal surface b.-tween said ihird grc-ove aiid said one end of sa4id crystal, the foiirth electrical coitact being bonded to said first longitudinal s@c-rfac-- cidiacen', sai,' third groove on the other side of said third groove from said third electrical contact, the fifth elec'Lr@cal contact being @bonded to said first longitudiiial surface idjacent said other end of said crystal near said othe@r side siirface of s,aid crystal. 21. A semicondur-tor strain gliqg.- compi:isin,-- (o) an elongate single semiconductor cry@,,tal of predetermined cryst,-dlo,-rapliie oriert,- ttion and of a -iqrst 24 pred,-termin-,d coii@l-uctivity 'Lype, siid semiconductor crystal defir@in,- first and secord opposed longitudinql surfaces, said md s-,co-iid IGngitudin-,tl siir.Laces and the crid sciriaces of said cryst-,d containiii-@ th,-rein ae@ive inipuxi'@y aLoms of a second predeterniipcd co,.iductivicy type to 'Lhereby define a sh@a-'Iow 13erip'iieral sur-face band of s,.iid s@-cond predeterniin-ed co-Tid-Lic'civity @,ype encirclin.- s,.,iid crystal exrlusive of Pts lotigittidin,-J sid-- s,@,rfaces, -.aid perip'iiaral sur10 fqce band of sal:d s-,cond Taredetermiqed condtictivity ',ype beiii@- e'@ectr"@cally isolited from the remaiD@n.@ first conductivily typ-- portion of said oryst-,il by the hi.-h inifcdpiiee barrier provided by the ji,-iictioii th,rebetween, sa@@d crystal having a groove --,@tendin15 tr@,.ns,,,ersely across s@dd pcripheral suiface baild and@ penc"ralin@, ilirough s,aid junctio,,i to thereby ipterr!7tot tii@ coitinuity of said p,-riph@,Nral surf-,tce baiid; (b) ia first contacl ohmically bonded to s,-Lid to s,@iid fLrs@L longit-ddinal suriace o'L sa;d crystal Nv,;thin 20 said periph-,ral surface band cnd adjacent said groove; and, (c) A s-,coiid clectri-,al contact ol@@niica!ly bonded to si@d i.,st lopgiLc@dii,,,,tl surfa.ce of said r-ryst,,,J itlithin said perirheral- sjr-face band and idjacent sa:id groove 25 on the opposi,e sid-.- of said groove from said first electrical contact. Reterinces Citei in ih@- file of this patent UNITED STATES PATENTS 30 2,738,259 @-@llis ------ Mar. 13, 1956 2,827,367 Cox ----- ------------ Mar. 18, 1958 31008,109 Starr ------------------- Nov. 7, 1961 3,049,685 Wri,@lit --------------- Aua. 14, 1962 ,_ 3,060,395 Sandven ---------------- Oct. 23, 1962 3a 3,084,300 c;,incliez ---------------- Apr. 2, 1963 3,089,108 Gong et al --------------- i@,lay 7, 1963 OT@HER REFERENCES Forst: "Appli-,atioiis of Se-@nico@iductor Transd,,,,cers iri 40 Strti@i Gages and Rigid Dynairometers," S.E.S.A. Proc@,,-dings, Vol. XVII, No. 1, March 1959, pages 142-.Q. RICI-TARD M. WOOD, Pr,,in,7ry Exainiiier.
